A charge pump (also referred as a switch capacitor voltage converter), is a DC-DC converter that usually uses a flying capacitor (also referred as “pumping” capacitor) to store energy, and to generate a required DC output voltage. Charge pump circuits are becoming more and more popular as the power supply management can be optimized, and chips can be integrated without using any inductor or transformer in the charge pump circuitry. With the control of a voltage control signal, the charge pump circuit can pump the energy from an input terminal with an input voltage to an output terminal for an output voltage through a capacitor by turning on and off switches in the charge pump circuit, so as to generate a DC output voltage.